Lotus E20 VD

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hardingfv32
hardingfv32
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Joined: 03 Apr 2011, 19:42

Re: Lotus E20 Renault

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N12ck wrote:That V is the wake created from the tubing to the rear wing I think
I believe this is the results of the system's function. I you accept that it is because of the duct's location at the bottom of the wing, then the system would have to make up for this lose of wing flow/performance just to get back to baseline. I do not think any of these DDRS systems have that kind of performance in them.

Brian

wesley123
wesley123
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Joined: 23 Feb 2008, 17:55

Re: Lotus E20 Renault

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N12ck is right. The V shape in the painting is because of flaow disruption by this central 'pillar'. This flow disruption is the reason why LMP's run swan neck supports to stop flow disruption on hte underside of the wing
"Bite my shiny metal ass" - Bender

bhall
bhall
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Re: Lotus E20 Renault

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bhallg2k wrote:
PhillipM wrote:^^Okay, looks like maybe there are vertical slits in the central pillar itself?
I noticed those quickly, but I didn't think much of them. However, I'm now pretty sure they are in fact the vents for the system.

I think they do indeed just help to stall the center portion of the wing (rectangular highlight), and I think the beam wing enclosure around the engine cover vent (circular highlight) is essentially just a diffuser to help draw out air from the vent.
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(Click to enlarge)

To bolster the idea that the duct slits are the vents, you can see below that they were covered so the team could differentiate the effects of the slits from the effects of the duct itself.
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(Click to enlarge)

I hope this is my final answer, because I hope my OCD on this subject has run its course.
While the central pillar on the McLaren is connected to the main plane further forward than the duct on the E20, one would expect to see some flow separation on the McLaren if such a placement were to cause it. However, it doesn't. Frankly, it would be a big hindrance to performance to have that level of flow separation at all times, because that's just straight-up lost downforce.
Image

wesley123
wesley123
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Joined: 23 Feb 2008, 17:55

Re: Lotus E20 Renault

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There is a clear case of disruption on the mclaren wing. You see a clear trail of paint going to the unpainted side of the wing.

Apart from that it doesnt give a clear indication since the area behind the pillar isnt seen.

Apart from that, the Lotus solution seems fatter and thus will have more disruption.
"Bite my shiny metal ass" - Bender

bhall
bhall
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Re: Lotus E20 Renault

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I don't interpret the errant Flo Vis on the McLaren that way. But, apart from that, since we know downforce is created on the underside of a wing, what's the benefit of running a central pillar that constantly sheds downforce? Apart from that, what makes air flow in this area immune to the oft-discussed Coanda effect that appears to work everywhere else?

My first reaction to the visible wake on the E20 was exactly as yours. But, after running it through the (very) old (and slightly defective) logic processor upstairs, there's really only one conclusion.

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hollus
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Re: Lotus E20 Renault

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And that conclusion is that the disrupted flo-vis corresponds to the DRS open state. But then the air would have to find somewhere else to go when DRS is closed, meaning that activating DRS would close that alternative exit.
But where is it? It should be very visible, and I wouldn't want to have it in the obvious place, just above the second wing plane, as shedding air there won't help downforce either.

There are two possibilities from here (not mutually exclusive):
a) They are only testing the stalling part, the alternative hole will appear after the summer break in a surprise place.
b) If the holes go above the second wing plane inside the end plates, they would normally suck air rather than expel it. Maybe send it from the high pressure area over the wing to the beam wing exit, making the slits neutral. his could help with air attachment and reduce the end plate vortexes in normal operation
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techF1LES
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Re: Lotus E20 Renault

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madly
madly
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Joined: 11 Feb 2010, 23:20

Re: Lotus E20 Renault

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hollus wrote:And that conclusion is that the disrupted flo-vis corresponds to the DRS open state. But then the air would have to find somewhere else to go when DRS is closed, meaning that activating DRS would close that alternative exit.
But where is it? It should be very visible, and I wouldn't want to have it in the obvious place, just above the second wing plane, as shedding air there won't help downforce either.
They simply could run this session with flow vis with always open DRS. Is it logical?

bhall
bhall
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Joined: 28 Feb 2006, 21:26

Re: Lotus E20 Renault

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hollus wrote:And that conclusion is that the disrupted flo-vis corresponds to the DRS open state. But then the air would have to find somewhere else to go when DRS is closed, meaning that activating DRS would close that alternative exit.
But where is it? It should be very visible, and I wouldn't want to have it in the obvious place, just above the second wing plane, as shedding air there won't help downforce either.

There are two possibilities from here (not mutually exclusive):
a) They are only testing the stalling part, the alternative hole will appear after the summer break in a surprise place.
b) If the holes go above the second wing plane inside the end plates, they would normally suck air rather than expel it. Maybe send it from the high pressure area over the wing to the beam wing exit, making the slits neutral. his could help with air attachment and reduce the end plate vortexes in normal operation
It's believe that the system is completely independent of DRS, that it's activated at a certain pressure.

madly
madly
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Re: Lotus E20 Renault

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Here we can compare new "Pelikan nose" (top) with the old one (bottom). Look how different are nose pillars.
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Last edited by madly on 27 Jul 2012, 22:02, edited 1 time in total.

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N12ck
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Re: Lotus E20 Renault

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they seem to have gone with Williams style nose pillars :D
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superdread
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Re: Lotus E20 Renault

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bhallg2k wrote:It's believe that the system is completely independent of DRS, that it's activated at a certain pressure.
A passive F-Duct would brush the limits of legality, as the teams agreed not to pursue that further in exchange for the DRS.

The explanation that it permanently channels air from the ears down above the beam wing and with a pressure switch (activated by the opening of the DRS) detaches the flow, at least in the middle of the main wing.

madly
madly
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Re: Lotus E20 Renault

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Alan Permane: ".. We spent the morning tuning the new aerodynamic device with various improvements after initial running in Hockenheim. ... The new aerodynamic system is now working well and will have its race debut in the near future."

James Allison: “We conducted valuable analysis of our latest aerodynamic developments on Kimi’s car this morning which help bring it a step closer to deployment in a race sometime in the future. ... Kimi was pretty happy overall, even this morning when we weren’t running the native downforce settings for this circuit. With the Hungary setup in the afternoon, Kimi was comfortable, quick, and happy with both specifications of dry tyre....”

So, system is working and will be employed in the near future.
Could we conclude, that this system was mainly prepared for faster tracks or rather not?

madly
madly
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Re: Lotus E20 Renault

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superdread wrote: A passive F-Duct would brush the limits of legality, as the teams agreed not to pursue that further in exchange for the DRS.
:lol: C'mon! And DDRS didn't pushed that limits?

Huntresa
Huntresa
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Re: Lotus E20 Renault

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Except Ferrari is this the car/team that has rly developed the most and best during the year?